CN112699562B

CN112699562B - Method and terminal for constructing power distribution network architecture

Info

Publication number: CN112699562B
Application number: CN202110002758.9A
Authority: CN
Inventors: 杨超; 罗朝升; 张静; 肖敏; 陈荣旭; 叶晓莹
Original assignee: State Grid Fujian Electric Power Co Ltd; Sanming Power Supply Co of State Grid Fujian Electric Power Co Ltd; Youxi Power Supply Co of State Grid Fujian Electric Power Co Ltd
Current assignee: State Grid Fujian Electric Power Co Ltd; Sanming Power Supply Co of State Grid Fujian Electric Power Co Ltd; Youxi Power Supply Co of State Grid Fujian Electric Power Co Ltd
Priority date: 2021-01-04
Filing date: 2021-01-04
Publication date: 2022-09-13
Anticipated expiration: 2041-01-04
Also published as: CN112699562A

Abstract

The invention provides a method and a terminal for constructing a power distribution network architecture, which are used for acquiring a predicted load value in a preset area and the total power generation amount of each power generation mode; sequencing all the total power generation amounts from low to high according to the cost of the power generation mode to obtain a first queue; subtracting the total power generation amount of each power generation mode one by one according to the sequence of the first queue from the predicted load value until the difference obtained when the total power generation amount of the Nth power generation mode is subtracted is less than or equal to 0, and taking the total power generation amount of the first queue which is positioned at the first N and belongs to the power generation modes of the distributed power supply as first power generation; determining a power distribution network architecture according to the technical guidance rules of the first power generation and power system; after the distributed power supply consumption capability is determined, the network planning is realized according to the determined distributed power supply consumption capability and relevant industry specifications, and the problems that the traditional power distribution network planning method cannot consume to the maximum extent, the advantages of the distributed power supply are utilized to the maximum extent, and the global optimization is realized are solved.

Description

Method and terminal for constructing power distribution network architecture

Technical Field

The invention relates to the field of power grids, in particular to a method and a terminal for constructing a power distribution grid architecture.

Background

With the increasing importance on the use and popularization of new energy, a large number of distributed power sources can be connected to a power distribution network in the foreseeable future; however, after the distributed power supply is connected to the power grid, the original passive power grid is changed into an active power grid, so that the power transmission, the voltage distribution, the power quality and the short-circuit current of the power grid are changed, and therefore, the protection, the control, the operation and the planning of the power grid are influenced greatly, and the power grid must adapt to the important change. At present, the conditions of massive access of various distributed power sources, bidirectional interaction between a client and a power distribution network, wide application of power electronic devices and the like make the deterministic planning and the operation theory of the traditional power distribution network difficult to meet the development requirements of the modern power distribution network.

The main task of the conventional power distribution network planning at present is to determine when and where to put on what type of power transmission line and the number of loops thereof in a planning period so as to meet the regional power load demand in the planning period, and on the premise of ensuring that various basic technical indexes such as line current carrying capacity, node voltage level, power supply reliability and the like are achieved, the minimization of system investment cost is pursued. In order to meet the new requirements of energy conservation and emission reduction policies on the development of power systems, environmental factors are increasingly considered in power distribution network planning work in recent years, and the 'cost minimization' (least cost) is no longer the only criterion for determining the quality of a planning scheme. The corresponding mathematical programming model is expanded to a certain extent no matter on an objective function or a constraint condition. However, the conventional power distribution network belongs to a standard passive network, and the planning method adopted by the related research can cope with all possible system operation scenes by adopting necessary capacity margin aiming at the load prediction result and conveniently find the optimal solution under various criteria, so that the method is relatively simple, the uncertainty of the load can be coped with by depending on a flexible network structure and enough capacity margin, the safety and the reliability of the system can be ensured, and the operation control method is relatively simple. In detail, the traditional power distribution network planning method is to adopt the maximum capacity margin (the condition that the most serious working condition is the small probability time) aiming at a certain load prediction result, so that the optimal solution for processing all the operation problems is found in the planning stage, and the traditional planning method is relatively simple. Meanwhile, the basic principle of planning and processing the distributed power supply by the traditional power distribution network is 'plug and forget', the traditional operation mode and control strategy are relatively simple, and the distributed power supply operates off-grid when the voltage is out of limit, so that the permeability of the distributed power supply is greatly reduced. Referring to fig. 9, the planning for accessing a large-scale distributed power source to a conventional power distribution network shows the following characteristics: (1) passive digestion: the traditional power grid planning mostly takes main grid power supply as a main grid, a source-grid one-way planning mode is embodied, after the distributed power supply is connected in a large scale, certain influences are brought to the electric energy quality, protection configuration and control mode of the traditional power grid, the traditional power grid does not carry out too much adjustment, only the distributed power supply is used as small disturbance, and the large-scale distributed power supply connection capacity cannot be actively absorbed. Thus, passive consumption of distributed power capacity appears. (2) Passive absorption: the method is influenced by a policy related to the networking of the distributed power supply, the distributed power supply is mostly self-generated, and the power grid access point is configured with reverse power protection. The distributed power supply is connected into the part of capacity passively consumed by the power grid, the output of the distributed power supply is not completely and actively absorbed, and the phenomena of wind and light abandonment are common. Thus, the distributed power output appears as passive absorption. (3) And (3) passive control: the traditional power grid has only transmitted or unsent instruction control on the output of the distributed power supply, has no real-time regulation control, only uses the distributed power supply as a negative load, cannot play the role to the maximum extent, and cannot optimize the running state. Thus, passive control of distributed power operation appears. Therefore, the traditional power distribution network planning only considers 'network-load', namely a power distribution network and load, and does not plan the power distribution network from the comprehensive angle of 'source-network-load', namely power supply, power distribution network and load, so that the problem that the distributed power supply with high permeability is accessed to the power distribution network is difficult to economically process.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the method and the terminal for constructing the power distribution network architecture are provided, and active control over the distributed power supply is achieved.

In order to solve the technical problem, the invention adopts a technical scheme that:

a method of constructing a power distribution network architecture, comprising the steps of:

s1, acquiring a predicted load value in a preset area and the total power generation amount of each power generation mode, wherein the power generation modes comprise distributed power generation and fixed power generation;

s2, sequencing all the total power generation amounts from low to high according to the cost of the power generation mode to obtain a first queue;

s3, subtracting the total power generation amount of each of the power generation modes one by one from the predicted load value according to the order of the first queue, and if a difference obtained when the total power generation amount of the nth power generation mode is subtracted is less than or equal to 0, taking the total power generation amount of the power generation modes of the first queue located in the first N and belonging to the distributed power supply as a first power generation amount;

and S4, determining the power distribution network architecture according to the first power generation and power system technical guide rule.

In order to solve the technical problem, the invention adopts another technical scheme as follows:

a terminal for constructing a power distribution network architecture, comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the following steps when executing the computer program:

s2, sorting the total power generation amount from low to high according to the cost of the power generation mode to obtain a first queue;

s3, subtracting the total power generation amount of each power generation mode one by one from the predicted load value according to the sequence of the first queue until the difference obtained when the total power generation amount of the Nth power generation mode is subtracted is less than or equal to 0, and taking the total power generation amount of the power generation modes of the first queue located in the first N and belonging to the distributed power supply as a first power generation sum;

The invention has the beneficial effects that: the method comprises the steps of obtaining the total power generation amount of various power generation modes, wherein the total power generation amount of distributed power generation and the total power generation amount of fixed power generation are included, determining the total power generation amount corresponding to each power generation mode capable of meeting the predicted load value by integrating the power generation cost of each power generation mode, planning a power distribution network architecture by starting from the demand, supply and cost, replacing the traditional planning from the perspective of only a grid structure and hardware configuration of the power distribution network, and enabling the advantages of distributed power generation to be fully exerted in the design of the power distribution network architecture.

Drawings

Fig. 1 is a flowchart illustrating steps of a method for constructing a power distribution network architecture according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a terminal for constructing a power distribution network architecture according to an embodiment of the present invention;

FIG. 3 is a schematic composition diagram of friendly and unfriendly loads of an embodiment of the present invention;

FIG. 4 illustrates a process for calculating a predicted load value according to an embodiment of the present invention;

FIG. 5 is a graph of the confidence level of an embodiment of the present invention;

FIG. 6 is a cumulative distribution function curve of the solar output of a photovoltaic system according to an embodiment of the present invention;

FIG. 7 is a schematic diagram illustrating a step of determining the power generation of a distributed power supply according to an embodiment of the present invention;

fig. 8 is a schematic diagram of an active power distribution network connection mode evaluation system according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of a shortcoming of a prior art power grid;

description of reference numerals:

1. a terminal for constructing a power distribution network architecture; 2. a processor; 3. a memory.

Detailed Description

In order to explain technical contents, achieved objects, and effects of the present invention in detail, the following description is made with reference to the accompanying drawings in combination with the embodiments.

Referring to fig. 1 and fig. 3 to 8, a method for constructing a power distribution network architecture includes the steps of:

From the above description, the beneficial effects of the present invention are: the method comprises the steps of obtaining the total power generation amount of various power generation modes, wherein the total power generation amount of distributed power generation and the total power generation amount of fixed power generation are included, determining the total power generation amount corresponding to each power generation mode which can meet the predicted load value by integrating the power generation cost of each power generation mode, planning a power distribution network architecture by starting from requirements, supply and cost, replacing the traditional planning from the perspective of only a grid structure and hardware configuration of the power distribution network, and enabling the advantages of distributed power generation to be fully exerted in the design of the power distribution network architecture.

Further, the step of obtaining the predicted load value in the preset area in S1 is specifically;

obtaining the predicted load value according to a long-term year-friendly load index preset in a preset area and load historical data of a preset number of years;

the long-range annual friendly load indexes comprise an interruptible load expected total amount, an interruptible load expected distribution, an electric automobile total amount, an electric automobile distribution, a power station changing total amount, a power station changing distribution, an electric automobile classification proportion, an adjustable load total amount, an adjustable load distribution and a load response coefficient;

wherein the total amount of interruptible load expectations and the distribution of interruptible load expectations are derived from development expectations of interruptible protocols; the total electric automobile amount, the electric automobile distribution, the total power change station amount, the power change station distribution and the electric automobile classification proportion are obtained through a long-term electric automobile development plan; the adjustable load total amount, the adjustable load distribution and the load response coefficient are obtained by performing trial operation statistics of a preset period in a trial area according to a real-time electricity price development plan or according to the adjustable load total amount, the adjustable load distribution and the load response coefficient in an advanced planning area with a perfect electricity price mechanism at home and abroad;

the prospective year represents any one year between the tenth year and the fifteenth year from the current year.

According to the description, various planning data are integrated during load prediction, friendly loads are predicted according to the planning data by using the predictability of the friendly loads, errors between the prediction data and actual data are reduced, the power exchange stations for charging the electric vehicles are counted as the friendly loads, the total amount of the electric vehicles is used as an estimated value, the electric vehicles can maintain electric power through charging besides batteries, and a certain range is reserved by the total amount of the electric vehicles during the prediction of the friendly loads to avoid overload of a power distribution network constructed according to the predicted load values caused by the fact that the actual load values exceed the predicted load values.

Further, the acquiring the total power generation amount of each power generation mode includes:

if the power generation mode is distributed power generation, calculating the credible output P of the distributed power _β Calculating the total power generation amount according to the credible output;

the credible output represents the ratio of actual power to total power which can be at least reached by the distributed power supply within a preset confidence interval.

According to the description, the total power generation amount is calculated according to the credible output of the distributed power supply, and the method of calculating the total power generation amount by using the calibration power of the distributed power supply is replaced, so that the method is closer to the actual total power generation amount of the distributed power supply, and the situation that the actual total power generation amount cannot supply sufficient load is avoided.

Further, the S3 specifically includes:

s31, subtracting the total power generation amount one by one according to the sequence of the first queue according to the predicted load value until the obtained difference is less than or equal to 0, obtaining each first total power generation amount as a subtraction number at the moment and a first power generation mode corresponding to the first total power generation amount, and respectively calculating a first proportion of each first total power generation amount in the sum of the first total power generation amounts;

s32, performing production simulation analysis with the lowest cost as a target according to the first proportion and the first power generation mode corresponding to the first total power generation amount in the first proportion to obtain a second power generation amount and a first power generation mode corresponding to the second power generation amount;

s33, calculating a second power generation mode which is a second power generation amount corresponding to the first power generation mode of distributed power generation, taking the second power generation mode as a new energy consumption capacity, judging whether the difference between the new energy consumption capacity and the new energy consumption capacity obtained by previous calculation is smaller than a threshold value, if so, taking the new energy consumption capacity as the first power generation mode, and executing S4; otherwise, marking the first power generation mode corresponding to the second power generation amount as the fixed power supply power generation and returning to the step S2.

According to the description, the proportion that each power generation mode can meet the load demand is calculated preliminarily, then, production simulation analysis is carried out according to the proportion to obtain each power generation mode with the optimal economic benefit and the corresponding generated energy, the power demand is met, meanwhile, the power generation cost is considered, the economic benefit is improved, the new energy consumption capacity is compared successively in the circulation process, the optimal new energy consumption capacity is obtained, and the environmental protection performance is guaranteed while the cost is considered.

Further, the S4 includes a substation planning step:

calculating the minimum total capacity of the transformer substationQuantity P ₂ ：P _Z ＝(P ₁ -P ₂ -P ₃ -P ₄ +P ₅ -P ₆ )×σ-P ₀ ；

Wherein, P _z To total capacity of the substation, P, at a preset voltage level ₁ To predict the load, P ₂ For loads below a voltage level greater than a predetermined voltage level, P ₃ Loads supplied by power supplies of a predetermined voltage class and power supplies below the predetermined voltage class, P ₄ For a direct-supply load of a predetermined voltage and a predetermined voltage class or higher, P ₅ For off-zone loads supplied within said predetermined area, P ₆ The load in the area supplied from the outside of the preset area in the preset area is sigma, and sigma is a capacity-load ratio; p ₀ The existing grade variable capacitance under the preset voltage grade in the preset area is obtained;

determining the spare capacity of the transformer substation according to the maximum value of the unfriendly load;

determining planned capacity of the transformer substation according to the minimum total capacity, the standby capacity and the determined planned capacity of the transformer substation;

and determining the address of the transformer substation according to the planned capacity and the technical guide rule of the power system.

According to the description, the planned capacity of the transformer substation is determined according to the minimum total capacity and the spare capacity, the address of the transformer substation is determined by combining the industry standard bricks, the transformer substation is planned, and the transformer substation is efficiently utilized while the safety is ensured.

Further, the S4 includes an energy storage plan:

calculating the actual charging power of the energy storage device: p _BES [n]×η _ES.C ；

Actual discharge power: p _ES [n]＝P _BES [n]×η _ES.D {P _BES [n]≥0；

Wherein, P _BES [n]＜0，P _ES [n]≥0，η _ES.C For charging efficiency, η _ES.D To discharge efficiency;

determining a power capacity P of the energy storage device _ESO ＝max{P _BES [n]}；

Determining theEnergy capacity E of energy storage device _ESO ＝E _ES.Dmax +E _ES.Cmax ×SOC _up -SOC _low ；

Wherein E is _ES.Dmax Accumulating the maximum discharge energy required for the energy storage device, E _ES.Cmax Accumulating a maximum charge energy, SOC, for energy storage devices _up For upper bound of the state of charge of the stored energy, SOC _low Is a lower bound on the energy storage state of charge.

According to the above description, energy storage is planned, and the power capacity and the energy capacity are determined by combining with the actual charge and discharge power, so that the planned capacity of the energy storage device is suitable for the actual scene.

Further, the predicted load value satisfies the following constraint:

the 110kV network power supply load is the power load for the whole society, the factory power load is 220kV and more than 220kV, the power grid direct supply load is 110kV power grid direct supply load, 220kV direct reduction 35kV load, 220kV direct reduction 10kV load, 35kV load and below 35kV network power generation load of a conventional power supply, and the distributed power supply has 90% credible output;

the credible output of a 10kV special line user load and the credible output of a 0.38kV distributed power supply are respectively calculated by taking 220kV direct supply 10kV load, 110kV direct supply 10kV load, 35kV direct supply 10kV load, 10kV direct supply 10kV load and 10kV distributed power supply as the load supplied by a 10kV public network.

According to the description, the predicted load value is verified by setting the constraint, the situation that the predicted load value deviates from the actual situation can be avoided, if the predicted load value does not meet the relevant constraint, the obtained predicted load value is not in accordance with the normal rule, at the moment, the relevant calculation of the subsequently constructed power distribution network is stopped, and the finally calculated power distribution network is prevented from deviating from the actual situation.

Further, the step S4 further includes power distribution network architecture comparison:

wherein NAV represents the net annual value, PB _i Indicates the total income, IC, of the i-th year _i Represents the total expenditure of the i-th year, r represents the discount rate, and n represents the economic incomeLife, (P/F, r, i) represents the current value coefficient of one payment, and (A/P, r, n) represents the fund recovery coefficient;

and selecting the power distribution network architecture with a larger net annual value.

According to the description, when the power distribution network architecture is selected, the net annual value is used as a standard, the economic benefits of the clean energy network access and power generation modes, namely power supply ends, are ensured, and meanwhile, the profit conditions can be considered in the construction process of the power network.

Further, the friendly load comprises a controllable load and an adjustable load which can completely follow a preset guiding mechanism.

According to the description, the adjustable load is further subdivided, the adjustable load and the controllable load which can completely follow the preset guiding mechanism are recorded as the friendly load together, and the accuracy of the structure for predicting the subsequent friendly load is improved.

Referring to fig. 2, a terminal for constructing a power distribution network architecture includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and when the processor executes the computer program, the processor implements the following steps:

Referring to fig. 1, a first embodiment of the present invention is:

the method comprises the following steps of predicting a total load value, a friendly load value and a non-friendly load value, wherein the predicted load value comprises a predicted total load value, a predicted friendly load value and a predicted non-friendly load value, and the step of obtaining the predicted load value in a preset area specifically comprises the following steps:

the method comprises the steps that a predicted total load value is obtained according to a typical power distribution network prediction method of distance before distance, specifically, a distant view year load value in a preset area is predicted first, and then a recent load value is predicted;

obtaining a prediction friendly load value according to a long-term view year-friendly load index preset in a preset area and load historical data of a preset number of years; specifically, referring to fig. 4, the overall load distribution of the distant view year is obtained according to the distant view year land planning and the load density index of the distant view year, the load distribution prediction of the distant view year is obtained according to the overall load distribution of the distant view year and the load index of the distant view year friend, further, the load and the electric quantity prediction of the distant view year friend can be further obtained according to the load distribution prediction of the distant view year friend, and the load and the electric quantity prediction of the middle year friend can be obtained by combining the historical load data;

predicting an unfriendly load value, namely predicting an overall load value-predicting a friendly load value;

wherein the expected total amount of interruptible load and the expected distribution of interruptible load are expected from the development of an interruptible protocol; the total electric automobile amount, the electric automobile distribution, the total power change station amount, the power change station distribution and the electric automobile classification proportion are obtained through a long-term electric automobile development plan; the adjustable load total amount, the adjustable load distribution and the load response coefficient are obtained by performing trial operation statistics of a preset period in a trial area according to a real-time electricity price development plan or according to the adjustable load total amount, the adjustable load distribution and the load response coefficient in an advanced planning area with a perfect electricity price mechanism at home and abroad;

the distant view year represents any year between the third year and the fifteenth year from the current year, and is often referred to as 2030, 2035 and the like;

the planned year represents any year after the current year;

horizontal year means any year between the fifth year and the tenth year from the current year;

friendly loads comprise controllable loads and adjustable loads capable of completely following a guiding mechanism; specifically, referring to fig. 3, according to the industry classification, loads are classified into uncontrollable loads, controllable loads and adjustable loads according to different degrees of load participation in power grid dispatching; uncontrollable loads, namely traditional loads, which have relatively fixed power consumption requirements and are the main component of the current distribution network load are represented by L1; the controllable load is mainly an interruptible load, usually achieved by means of an economic contract (agreement). The method is characterized in that a power company signs with users, and the users interrupt and reduce loads according to contract rules at the time of a system peak and in an emergency state, so that the method is an important guarantee for the management of a demand side of a power distribution network and is represented by L3; the adjustable load refers to a load which cannot completely respond to power grid dispatching but can follow a guidance mechanism such as a time-phased step price and the like to a certain extent so as to adjust the power utilization requirement, and is represented by L2; the overall load L of the active power distribution network is L1+ L2+ L3; the adjustable loads comprise adjustable loads which completely follow a guide mechanism and adjustable loads which cannot follow the guide mechanism, the adjustable loads are classified into controllable loads and labeled L2A, the adjustable loads are classified into uncontrollable loads and labeled L2B, and the overall loads of the active power distribution network are divided into two types from the perspective of whether the overall loads are controlled or not: friendly and unfriendly loads; friendly loads include L3 and L2A, unfriendly loads include L1 and L2B; in order to characterize the degree of control of the load in an active distribution network, a load active control factor λ is defined: λ ═ L2A + L3)/L, where λ is the proportion of friendly load in the overall load of the distribution network;

in an alternative embodiment, for an electric automobile adopting slow charging, conventional charging and fast charging modes, the electric automobile can participate in power grid dispatching in a mode of responding to the stepped electricity price, and the loads belong to adjustable loads; for the electric automobile charged by adopting the mode of replacing the battery in the power exchanging station, the power grid dispatching can be participated in by the power exchanging station, and the load belongs to controllable load;

the predicted load value satisfies the following constraints:

the credible output of a 10kV special line user load-0.38 kV distributed power supply is calculated by taking 220kV direct supply 10kV load, 110kV direct supply 10kV load, 35kV direct supply 10kV load, 10kV direct supply 10kV load and 10kV distributed power supply as the load supplied by a 10kV public network;

the step of acquiring the total power generation amount of each power generation mode comprises the following steps:

if the power generation mode is distributed power generation, calculating the credible output P of the distributed power _β Calculating the total power generation amount according to the credible output; wherein beta denotes an execution interval, e.g. P _β 90%, and β 90%, representing that the probability of 90% of the actual power of the distributed power source accounts for 90% of the total power;

the credible output represents the ratio of actual power to total power at least capable of being reached by the distributed power supply in a preset confidence interval;

in an alternative embodiment, P _β The probability density function or the accumulative distribution function processed by the distributed power supply can be calculated; the output risk degree alpha of the distributed power supply is 1-beta, and the value of alpha can be adjusted according to the reliability requirement;

referring to fig. 5 and fig. 6, the prediction of the photovoltaic power generation output of a certain area is taken as an example: the solar illumination intensity is 0 at night, and the distribution is approximately in accordance with the normal distribution in the daytime, so that a certain confidence coefficient is determined, and a credible value of the light intensity curve can be obtained; in fig. 5, the solid line is a typical sunlight intensity time sequence variation curve, the dotted line represents a credible light intensity curve, and L α is a credible light intensity corresponding to a certain risk;

according to a general photovoltaic power generation model, the photovoltaic output can be approximately regarded as a unary linear function determined only by the illumination intensity, so that the photovoltaic output and the light intensity have an approximate distribution trend, which is illustrated by an accumulated distribution function of the photovoltaic output throughout the day, as shown in fig. 6; in FIG. 6, α represents the photovoltaic output risk, and P1- α represents the photovoltaic credible output corresponding to the risk α, i.e. the probability that the photovoltaic output P is located at [0, P1- α ] is α; PN represents the photovoltaic rated output, and when the risk degree reaches 100%, the credible output is PN; setting the cumulative distribution function of the photovoltaic output as f (P), and establishing an equation f (P) ═ α, so as to obtain the credible photovoltaic output P1- α under the risk α: finally, by combining the regional distributed power supply general installation and the unit distributed power supply credible output value, a distributed power supply credible output prediction model Pz alpha of the planning region perspective year is obtained;

wherein, Pz alpha is credible output of a distributed power supply of the regional perspective year; pz is the installed total capacity of the distributed power supply in the distant view year of the region; p alpha is unit distributed power supply credible output; p is the installed capacity of the unit distributed power supply;

referring to fig. 7, the following embodiments:

as hydropower, thermal power and the like which can be developed in a preset area are limited, the increase of the hydropower generation and the thermal power generation is very slow at present, and a trend of rapidly developing new energy exists in the future, the condition that the finally determined first power generation mode does not include distributed power generation is not considered;

s32, performing production simulation analysis with the lowest cost as the target according to the first proportion and the first power generation mode corresponding to the first total power generation amount in the first proportion to obtain a second power generation amount and a first power generation mode corresponding to the second power generation amount;

s33, calculating a second power generation mode, which is a second power generation amount corresponding to the first power generation mode of distributed power generation, and using the second power generation mode as a new energy consumption capability, determining whether a difference between the new energy consumption capability and a previous new energy consumption capability calculated in the previous time is smaller than a threshold, if so, using the sum of the new energy consumption capability and the previous new energy consumption capability as the first power generation mode, and executing S4 (since the previous first power generation mode is marked as a fixed power when the new energy consumption capability is calculated in this time); otherwise, marking the first power generation mode corresponding to the second power generation amount as a fixed power supply to generate power and returning to the step S2;

if the new energy consumption capability is calculated for the first time, the previous new energy consumption capability is set to be 0;

s34, determining the access voltage grade of the distributed power supply according to the DG access power distribution network design specification Q/GDW11147-2013, and referring to table 1; DG (Distributed Generation);

TABLE 1

S4, determining a power distribution network architecture according to the first power generation and power system technical guide rule;

wherein, the technical guide rule of the power system indicates GB/T38969-2020;

s4 includes substation scheme making:

calculating minimum total capacity P of transformer substation ₂ ：P _Z ＝(P ₁ -P ₂ -P ₃ -P ₄ +P ₅ -P ₆ )×σ-P ₀ ；

Wherein, P _z Is the total capacity, P, of the substation at a preset voltage level ₁ To predict the load, P ₂ For loads below a voltage level greater than a predetermined voltage level, P ₃ Loads supplied by power supplies of a predetermined voltage class and power supplies below the predetermined voltage class, P ₄ For a direct-supply load of a predetermined voltage and a predetermined voltage class or higher, P ₅ For extra-zone loads, P, supplied within said predetermined area ₆ The load in the area supplied from the outside of the preset area in the preset area is sigma, and sigma is a capacity-load ratio; p ₀ The existing grade variable capacitance under the preset voltage grade in the preset area is obtained;

in an alternative embodiment, P ₁ To predict unfriendly load values;

determining a substation address according to the planned capacity and the technical guide rule of the power system;

s4 includes medium voltage grid construction:

(1) determining a wiring mode: carrying out wiring mode analysis according to the output of the distributed power supply, the load density after the novel load is controlled or the novel load is actively adjusted, and the coexistence state of multiple power supply points and loads in the power supply area; the active reconstruction of the wiring mode is realized by taking the minimum network loss, the maximum utilization of the distributed power supply or the highest reliability of the distributed power supply as targets, please refer to fig. 8, and on the basis of the determined predicted load value and the first power generation sum, the selection standard of the wiring mode is established from the three aspects of the technology, the economy and the adaptability;

(2) and (3) determining the outgoing line number: according to the characteristic that the load density of an active power grid is low, the outgoing line return number of a transformer substation is reduced, the growth speed of the load density (direct supply load density of the transformer substation) is reduced due to the development phase change of the active power grid, so that the outgoing line return number of the transformer substation in the planning year is reduced under the condition that other conditions are the same, and the development of novel loads and distributed power supplies is greatly influenced by government energy policies, so that the load prediction of the active power grid has larger uncertainty compared with the traditional power grid; therefore, the outgoing line number should be controlled as much as possible in active power distribution network planning, so that limited outgoing line interval resources can adapt to different power consumption requirements in the planning area in the future;

(3) and (3) line selection determination: the access of the distributed power supply and the energy storage device enables the power distribution network to have a plurality of power supply points, the real-time reconstruction of the active power distribution network in a normal operation state and the complex island combination mode and load transfer mode in a fault state enable the power flow size and direction of each section of the power distribution network to have multiple possibilities, and in addition, the output of the wind and light storage system and the random fluctuation of various loads are added, so that the active power distribution network line selection is a complex problem. In technical indexes, probability load flow calculation can be carried out on the active power distribution network, and the line selection should meet the requirements of N-1 verification and reliability within a certain confidence interval. A line selection optimization model can be established by taking the technical indexes as constraint conditions and taking the optimal economy of the whole network as a target function;

time sequence flow analysis: besides using basic information such as a power grid structure, element parameters and the like in a conventional method, the method also needs to additionally use operation data of the randomly-changed elements, such as a load operation curve, a generator operation curve, an energy storage device operation curve and the like; the load operation curve generally refers to the relationship curve of the active power and the time, and in a special case, a reactive operation curve is considered. The generator operating curve generally refers to an active operating curve and a reactive operating curve;

calculating probability load flow: with the rapid development of distributed power supplies, a power system will develop from a single scheduling mode of 'power generation tracking load' to 'source-grid-load' active scheduling in the future, and meanwhile, both the power supply side and the load side have uncertainty. Therefore, the probabilistic power flow becomes an important basis for solving uncertain factors of the power system, AND random injection quantity should be added on the basis of traditional probabilistic power flow calculation, so that the power flow direction is changed from a single (or fixed) flow direction mode to a source-load bilateral interaction mode to adapt to the uncertainty of an AND (intelligent power grid);

s4 includes energy storage planning:

calculating the actual charging power of the energy storage device: p _ES [n]＝P _BES [n]×η _ES.C ，P _BES [n]＜0；

Actual discharge power: p _ES [n]＝P _BES [n]×η _ES.D {P _BES [n]≥0；

Wherein, P _BES [n]＜0，P _ES [n]≥0，η _ES.C For charging efficiency, eta _ES.D To the discharge efficiency;

Determining an energy capacity E of the energy storage device _ESO ＝E _ES.Dmax +E _ES.Cmax ×SOC _up -SOC _low ；

Wherein, E _ES.Dmax Accumulated maximum discharge energy required for the energy storage device, E _ES.Cmax Accumulating a maximum charge energy, SOC, for energy storage devices _up For upper bound of the state of charge of the stored energy, SOC _low Is a lower bound on the energy storage state of charge.

The second embodiment of the invention is as follows:

a method for constructing a power distribution network architecture, which is different from the first embodiment in that:

the active power distribution network added with the distributed power supply needs to be added with consideration to the situation of 'network' and 'load' when the traditional power distribution network plans the current situation of the power grid, namely, on the basis of diagnosing and analyzing the bottleneck of meeting the load requirement of the power grid and finding out the weak relief of the power grid for the power grid in the past on three aspects of the equipment situation, the network frame situation and the running situation of the power grid, the analysis of the distributed power supply and the energy storage system and the bottleneck analysis of the distributed power supply acceptance of the power grid are needed to be added;

the distributed power supply comprises a photovoltaic power generation power supply, a wind power generation power supply and other new energy power generation power supplies;

before S1, further comprising:

(1) analyzing the current situation of the distributed power supply:

on the aspect of equipment, whether the access voltage grade and installed capacity of the existing distributed power supplies of various types are reasonable or not is analyzed according to the technical guide of the power system; whether the distributed power supply protection device is configured according to the standard, if so, configuring a high/low voltage protection device, a high/low frequency protection device, an anti-islanding protection device, a recovery grid-connected protection device, an overcurrent and short-circuit protection device, an accident disconnection device and the like;

in terms of operation, the operation condition of the distributed power supply is analyzed from the power generation condition, the daily active curve and the voltage quality:

the power generation condition is as follows: describing annual power generation capacity and power generation capacity curves of the distributed power supply, wherein the annual power generation capacity and power generation capacity curves comprise a power generation capacity curve of a month in the last year and a curve formed by setting the annual power generation capacity of the distributed power supply at present, and analyzing the permeability of the distributed power supply in a key way; the distributed power supply permeability is an important index for measuring the consumption level of the distributed power supply after the distributed power supply is connected into a power grid, and is defined as the ratio of the total generated energy of the distributed power supply to the power consumption of a system; if the permeability of the distributed power supply is higher than a reasonable value, adverse effects can be brought to the safety of a power grid, the cost for transforming the power grid is increased, and the utilization efficiency of the distributed power supply is also reduced;

active curve: analyzing a typical daily power generation power curve, and calculating the output load rate of the distributed power supply; comparing the power output with the load of an access line or a transformer substation, and analyzing the peak shaving effect of the distributed power on the load of the power grid;

voltage quality of the network access point: and after the power distribution network is connected to the distributed power supply, the voltage at each load node of the feeder line is increased. Therefore, whether the grid-connected point of each distributed power supply is over-voltage needs to be analyzed;

(2) analyzing the bottleneck of the distributed power supply accessing to the power grid:

the capacity of the distributed power supply capable of being connected into the power distribution network is mainly restricted by a transformer substation and a line, wherein the limiting conditions of the transformer substation on the access of the distributed power supply mainly comprise the residual interval of the transformer substation, the maximum load level and the like; the limiting conditions of the line to the access of the distributed power supply comprise line model, line full length, load level, reactive compensation and the like.

The method comprises the following steps of: after the distributed power supply is connected, power is not transmitted to a superior power grid through a main transformer, so whether the generated energy of the distributed power supply can be consumed by the maximum load of a transformer substation corresponding to an access node or not is an important influence factor for restricting the connection of the distributed power supply; the remaining interval of the transformer substation: for a large-capacity distributed power supply, a special line is required to be accessed into a transformer substation. The number of the residual intervals in the transformer substation restricts whether the distributed power supply can adopt a special line access mode; ③ load characteristics: the load near the distributed power supply access node meets the requirements on the quality and the voltage level of electric energy, and the matching of the fluctuation of the load and the power generation characteristic of the distributed power supply is favorable for expanding the local receiving capacity of the distributed power supply and improving the access capacity of the distributed power supply; fourthly, line transmission: the transmission capacity of the line is determined by the line model, and when the capacity of the distributed power supply is expanded to a certain degree, the transmission capacity of the line cannot meet the maximum output power of the distributed power supply, so that the access power of the distributed power supply is limited; in addition, the distributed power supply brings network loss change in the process of line transmission, so that the original line model and length need to be reasonably determined aiming at the access of distributed power generation, and the economic operation of a power grid after the distributed power supply is connected to the grid is ensured; spare capacity: in order to meet the safety and reliability of the system, the power distribution network always reserves a certain spare capacity for system load transfer and distributed power supply access, so that the original operation state of the system is changed, and the spare capacity and the voltage regulation capacity of the system are influenced. When the distributed power supply output is lost, the voltage of the system is fluctuated. Therefore, aiming at the problem of distributed power supply access, adjustment means such as energy storage can be considered to be added, and on-site standby is realized; voltage deviation: the access of the distributed power supply changes the flow direction of active power of the original power grid, and simultaneously changes the flow direction of reactive power of the power grid, so that the reactive voltage level of the power grid is influenced; when the system voltage is out of limit, a protection action is caused, and the safe operation of a power grid is influenced;

in summary, after the distributed power supply is connected, corresponding reactive compensation measures such as parallel capacitors and reactive compensator installation should be taken, so as to improve the output characteristics of the distributed photovoltaic power supply and increase the construction scale of the distributed power supply.

The third embodiment of the invention is as follows: a method for constructing a power distribution network architecture, which is different from the first embodiment or the second embodiment in that:

the step S4 further includes power distribution network architecture comparison:

(1) net annual value method

Wherein NAV represents the net annual value, PB _i Indicates the total income, IC, of the i-th year _i Representing the total expenditure of the ith year, r representing the discount rate, n representing the economic service life, (P/F, r, i) representing the coefficient of the current value of one payment, and (A/P, r, n) representing the coefficient of capital recovery;

selecting the power distribution network architecture with a larger net annual value;

(2) minimum cost method

And calculating the total cost of each power distribution network architecture scheme, and preferably calculating the scheme with a lower annual cost value. The minimum cost method can be used for comparing and selecting mutually exclusive schemes under the condition of same benefit or equivalent benefit;

(3) cost-benefit comparison method

Respectively calculating benefit annual value and cost annual value of each power distribution network architecture scheme, and preferably calculating a scheme with a high benefit-cost ratio; the benefit-cost ratio method can be used for the ratio selection of independent schemes and item packages with possibly different benefits and costs;

E＝PB/IC

wherein E identifies the ratio of benefit to cost, PB represents the total benefit year value, in units: ten thousand yuan; IC represents the total cost annual value, in units: ten thousand yuan;

s4 is followed by evaluating the grid architecture scenario:

(1) and (3) cost evaluation:

initial investment cost: calculating the annual value of the investment cost of the project by taking the total investment of the project as a base value _n ＝I ₀ X (A/P, r, n), wherein I ₀ Represents the total investment of the project, unit: ten thousand yuan; IC (integrated circuit) _n Represents the annual value of project investment, unit: ten thousand yuan; r represents the reduction rate, and n represents the economic service life; (A/P, r, n) represents a capital recovery factor;

operation and maintenance cost: the operation and maintenance cost is determined by investigation or statistics, and if the operation and maintenance cost is difficult to obtain, the operation and maintenance cost can be approximately calculated by adopting a proportionality coefficient method, wherein the formula is OC _n ＝k _l ×I ₀ Wherein, OC _n Represents the operation and maintenance of the project into the annual value, unit: ten thousand yuan; k is a radical of formula ₁ A proportional coefficient representing the operation and maintenance cost in the total investment is generally an average value of historical three years in the region;

cost of retirement: the retired cost is obtained by deducting the processing cost and the residual value, and can be approximately calculated by adopting a proportional coefficient method, wherein the formula is OT _n ＝(k ₂ -0.05)×I ₀ X (A/F, r, n) where OT _n Represents the retirement cost year value of the project, and the unit is: ten thousand yuan k ₂ A proportional coefficient representing the proportion of the treatment cost to the total investment is generally an average value of historical three years in the region; (A/F, r, n) represents a final value-to-annual value coefficient;

IC for total cost _n +OC _n +OT _n IC represents the project assembly current year value, unit: ten thousand yuan;

(2) benefit assessment

Increasing power supply benefit

Calculating power supply capacity: the power supply capacity calculation adopts a power supply algorithm (algorithm 1) based on the power supply safety standard of the power distribution network or an algorithm (algorithm 2) based on the N-1 safety criterion. The algorithm 1 is adopted for the single-line single-change or medium-voltage line single-radiation operation condition of the high-voltage transformer substation, and the algorithm 2 is adopted for the non-single-line single-change or medium-voltage line contact condition of the high-voltage transformer substation.

And when the transformer substation is operated by a single line single transformer, the power supply capacity is the load allowed to be lost by the power supply safety standard under the condition of N-1 fault, namely the power supply capacity of the transformer substation is 12 MW. Under the condition of non-single-wire single-transformer operation of a transformer substation, the power supply capacity is the comprehensive power supply capacity of a main transformer and an incoming line, the maximum power supply load under a certain overload coefficient is considered when the power supply capacity of the main transformer and the incoming line is N-1 fault, and the formula is as follows:

SC _i ＝min(1.3×SC _N-1,S ,1.1×SC _N-1,L )；

wherein, SC _N-1,S The maximum load which can be supplied by the residual transformer after the main transformer with the maximum capacity is shut down is represented by the following unit: MW; SC (Single chip computer) _N-1,L The maximum load that the remaining line can supply after the maximum capacity inlet wire is shut down is represented, unit: MW; SC (Single chip computer) _i The maximum power supply capacity of the ith substation is represented as follows: MW;

the power supply capacity of the high-voltage associated power grid is the accumulated sum of the power supply capacities of the transformer substations within the range of the associated power grid, and the formula is as follows:

wherein N represents the number of associated grid substation seats; SC represents the maximum power supply capacity of the associated grid, unit: MW;

the power supply capacity of the medium-voltage single radiation line is a load which is allowed to be lost by the power supply safety standard under the condition of N-1 fault, namely the power supply capacity of the line is 2 MW; the power supply capacity of the medium-voltage group of the contact lines is the maximum power supply load when the contact feeder group N-1 fails, and the formula is as follows:

wherein S is _i And (3) representing the power supply capacity of the ith feeder, unit: MW;

and (3) calculating the increased power amount: only the amount of boost power within the power supply safety criteria, i.e. the product of the safe boost load and the maximum load utilization hours, is considered. The annual safe power supply load is predicted to be the smaller of the power supply capacity and the power supply load, and the calculation formula is as follows:

VP _i ＝[L _safeA -L _safeB ]×k _m ×Tmax/10；

L _safe ＝min(L,SC)

wherein, VP _i Represents the increased power amount in the ith year in units of: ten thousand kWh; l represents the predicted (actual) load, in units: MW; SC represents power supply capability, unit: MW; l is _safeB Representing the safety power supply load of the associated power grid before project implementation, unit: MW; l is _safeA Representing the safety power supply load of the associated power grid after the project is implemented, unit: MW; SC (Single chip computer) _BP And (3) representing the power supply capacity of the associated power grid before project implementation, unit: MW; SC (Single chip computer) _AP And (3) representing the power supply capacity of the associated power grid after the project is implemented, wherein the unit is as follows: MW; tmax represents the number of maximum load utilization hours, unit: h; k is a radical of _m Expressing an augmented power supply amount allocation coefficient, and providing a ratio of a power supply capacity improvement value of the associated power grid to a power supply margin;

the increased power supply amount of the medium-voltage distribution network planning project can be approximately calculated according to the following formula:

VP _i ＝(SC _AP -SC _BP )×Tmax/10

wherein, SC _BP Represents the power supply capacity before project commissioning, unit: MW; SC (Single chip computer) _AP Represents the power supply capacity after project operation, unit: MW; VP _i Represents the amount of boost power, unit: ten thousand kWh;

and (3) increasing the power supply benefit calculation: calculating the increased power supply benefit of the planning project year by year, distributing the increased power supply benefit according to the proportion of the power grid cost of each voltage grade to the total cost, converting the calculation result into the current value, and calculating the benefit annual value. The calculation formula is as follows:

PB _Pn ＝PB _P ×(A/P,a,n)

wherein, PB is _P Representing the current value of boost power efficiency, PB _Pn The annual value of the increased electric quantity benefit is expressed, and the unit is ten thousand yuan; Δ R represents the price difference of electricity purchased and sold in units: meta \ kWh; k is a radical of formula _U Representing the power increase capacity benefit apportionment coefficient; a represents a discount rate; m is a unit of _U Representing a certain voltage level fixed asset total; m is _Σ The total amount of fixed assets of the regional power grid (not counting extra-high voltage, alternating current and direct current and other cross-regional networking projects) is represented by the unit: billion yuan;

second benefit of reliability

And (3) calculating the reduction value of the number of hours of power failure of each household:

for a high-voltage planning project, the reduction value of the number of hours of power failure of each household caused by the reason of a high-voltage distribution network in the range of the associated power grid is calculated;

the N-1 loss load of the associated power grid before and after project implementation should be calculated, and then a reliability improvement value is obtained. The formula is as follows:

wherein, Δ T represents the reduction value of the number of power failure hours per household of the associated power grid, and the unit is as follows: h; t represents the power failure hour caused by the reason of the high-voltage distribution network of the associated power grid before the project is put into operationThe number is approximately replaced by the number of power failure hours caused by the high-voltage power failure reason in the area, and the unit is as follows: h; l is _N-1,SB Representing the main transformer and the line N-1 verification loss load before project implementation, the unit is as follows: MW; l is a radical of an alcohol _N-1,SA The main transformer and line N-1 verification loss load after the project implementation is represented, unit: MW;

for the medium voltage planning project, the reduction value of the number of hours of power failure of each user caused by the medium voltage distribution network in the range of the associated power grid should be calculated. Calculating the associated power grid power outage hours before and after the implementation of a planning project according to DL/T 'Power distribution network reliability assessment guide rules', and further solving a power outage hour reduction value;

calculating a power shortage amount reduction value: and calculating the reduction value of the power shortage amount according to the reduction value of the average power failure time of the household before and after project implementation and the average load value of the related power grid after project implementation. The formula is as follows:

VP _R ＝(ΔT×P _A ×Tmax/8760)/10

wherein, VP _R Represents a reduced value of the power shortage of the planning project, and the unit is: ten thousand yuan; p is _A And (3) representing the maximum load predicted value of the associated power grid after project operation, unit: MW; t max represents the maximum load utilization hours, unit: hours;

and (3) calculating the reliability benefit: and calculating the reliability benefit value according to the reduction value of the power shortage amount before and after the project implementation, and multiplying the power failure loss cost of the unit electric quantity. The formula is as follows:

PB _R ＝k _r ×VP _R

wherein k is _r And (4) representing the power failure loss cost of unit electric quantity, and adopting the value of the power generation ratio, namely the GDP (gas insulated switchgear)/the power supply quantity of the region.

③ reducing loss benefit

And (3) calculating loss reduction electric quantity: and (3) calculating a related power grid loss value before and after the implementation of a planning project according to DL/T686, and further calculating loss reduction electric quantity:

ΔPB＝ΔA _B -ΔA _A

where Δ PB represents the loss reduction power, unit: ten thousand kWh; delta A _B Representing the power loss of the associated power grid before the implementation of a planning project, unit: ten thousand kWh; delta A _A And (3) representing the power loss of the associated power grid after the implementation of a planning project, unit: ten thousand kWh;

calculating the loss reduction benefit annual value:

PB _L ＝ΔPB×P _P

wherein, PB is _L Represents the annual value of the loss reduction benefit, and the unit: ten thousand yuan; Δ PB represents loss reduction power, unit: ten thousand kWh; p is _P Represents the electricity purchase price, unit: yuan/kWh;

and fourthly, delaying the investment benefits of the power grid: and (3) calculating the investment delay benefits brought by the fact that the distributed power supply participates in load balancing and further the construction of lines and transformer substations is reduced:

PB _G ＝P _G ×K _p ×(R _G +R _Z )×(A/P,a,n)

wherein, P _G Represents installed capacity of the distributed power supply, unit: MW; k _p Representing the credible output of the distributed power supply, unit: MW; r _G And (2) representing the transformation investment of unit capacity, unit: ten thousand yuan/MVA; r _Z Represents the line investment per unit capacity, unit: ten thousand yuan/MVA;

the total benefit: the increased power supply benefit annual value, the reliability benefit annual value, the loss reduction benefit annual value and the delay power grid investment accumulation are added to obtain the total benefit annual value after the implementation of a planning project:

PB＝PB _P +PB _R +PB _L +PB _G

wherein the content of the first and second substances, _PB represents the total annual benefit value in units: ten thousand yuan.

Referring to fig. 2, a fourth embodiment of the present invention is:

a terminal 1 for constructing a power distribution network architecture, comprising a processor 2, a memory 3 and a computer program stored in the memory 3 and operable on the processor 2, wherein the processor 2 implements each step of the first, second or third embodiment when executing the computer program.

In summary, the present invention provides a method and a terminal for constructing a power distribution network architecture, wherein in the power distribution network architecture planning, after determining the consumption capability of a distributed power source by using a source-network collaborative planning method, the network planning, i.e. the planning of a high-voltage and medium-voltage distribution network scheme, is realized according to the determined consumption capability of the distributed power source and relevant industry specifications; planning of a distributed power supply access scheme is achieved through source access; checking the rationality of the access scale and the position of the distributed power supply through a network; the method solves the problems that the traditional power distribution network planning method cannot furthest consume, maximally utilize the advantages of the distributed power supply and realize global optimization, provides active power distribution network planning standards and decision basis for power distribution network planning technicians, can break through the problem that the traditional power distribution network only plans once from the perspective of grid network structure and hardware configuration, abandons the access of the distributed power supply only by considering economic benefits in the planning process, furthest improves the consumption capability of the distributed power supply and furthest exerts the supporting function of the distributed power supply, verifies the rationality of the access scale and the position of the distributed power supply through a network, analyzes the credible output of different probabilities of the distributed power supply according to the 8760-hour output condition of the distributed power supply in the whole year on the aspect of power electric quantity balance, combines the characteristics of diversified loads, and deducts the non-grid power supply load capable of being efficiently utilized, forming power balance results under different probabilities, adopting a benefit cost analysis method to realize economic and technical analysis of different types of planning projects, researching an optimal sorting method of the planning projects under different constraint conditions, and providing a simplified calculation method and contents from benefit characteristics of various projects; the problem that investment benefit analysis of traditional power distribution network planning is weak is solved, and a technical-economic comparison analysis method for distributed power access is provided through repeated analysis.

The above description is only an embodiment of the present invention, and is not intended to limit the scope of the present invention, and all equivalent modifications made by the present invention and the contents of the accompanying drawings, which are directly or indirectly applied to the related technical fields, are included in the scope of the present invention.

Claims

1. A method of constructing a power distribution network architecture, comprising the steps of:

the step S4 includes substation scheme establishment:

calculating the minimum total capacity P of the transformer substation under the preset voltage level _Z ：P _Z ＝(P ₁ -P ₂ -P ₃ -P ₄ +P ₅ -P ₆ )×σ-P ₀ ；

Wherein, P _z Is the minimum total capacity, P, of the substation at a preset voltage level ₁ To predict the load, P ₂ For loads below a voltage level greater than a predetermined voltage level, P ₃ Loads supplied by power supplies of a predetermined voltage class and power supplies below the predetermined voltage class, P ₄ For direct-supply loads at and above a predetermined voltage level, P ₅ For extra-zone loads, P, supplied within said predetermined area ₆ The load in the area supplied from the outside of the preset area in the preset area is sigma, and sigma is a capacity-load ratio; p is ₀ The existing level variable capacitance under the voltage level is preset in the preset area;

determining planned capacity of a transformer substation according to the minimum total capacity and the standby capacity;

the S4 includes an energy storage plan:

calculating the actual charging power of the energy storage device: p is _ES [n]＝P _BES [n]×η _ES.C ，P _BES [n]＜0；

Actual discharge power: p _ES [n]＝P _BES [n]×η _ES.D ， P _BES [n]≥0；

Wherein eta is _ES.C For charging efficiency, η _ES.D To the discharge efficiency;

Wherein, E _ES.Dmax Accumulating the maximum discharge energy required for the energy storage device, E _ES.Cmax Accumulating a maximum charge energy, SOC, for energy storage devices _up For upper bound of the state of charge of the stored energy, SOC _low Is a lower bound on the energy storage state of charge;

and after the step S4, further comprising power distribution network architecture comparison:

selecting the power distribution network architecture with a high net annual value.

2. The method according to claim 1, wherein the step of obtaining the predicted load value in the preset area in S1 is specifically;

wherein the total amount of interruptible load expectations and the distribution of interruptible load expectations are derived from development expectations of interruptible protocols; the total quantity of the electric automobiles, the distribution of the electric automobiles, the total quantity of the battery replacing stations, the distribution of the battery replacing stations and the classification proportion of the electric automobiles are obtained through a long-term electric automobile development plan; the adjustable load total amount, the adjustable load distribution and the load response coefficient are obtained by performing trial operation statistics of a preset period in a trial area according to a real-time electricity price development plan or according to the adjustable load total amount, the adjustable load distribution and the load response coefficient in an advanced planning area with a perfect electricity price mechanism at home and abroad;

the prospective year means any one of the years between the third year and the fifteenth year from the current year.

3. The method according to claim 1, wherein the obtaining of the total power generation amount of each power generation manner from the predicted load value in the preset region and the total power generation amount of each power generation manner comprises:

4. The method according to claim 1, wherein the S3 is specifically:

s33, calculating a second power generation mode which is a second power generation amount corresponding to the first power generation mode of distributed power generation, using the second power generation mode as a new energy consumption capacity, judging whether the difference between the new energy consumption capacity and the new energy consumption capacity obtained by previous calculation is smaller than a threshold value, if so, using the new energy consumption capacity as the first power generation mode, and executing the S4; otherwise, marking the first power generation mode corresponding to the second power generation amount as the fixed power supply power generation and returning to the step S2.

5. A method of constructing a power distribution network architecture according to claim 3, wherein the predicted load values satisfy the following constraints:

6. The method of claim 2, wherein the friendly loads comprise controllable loads and adjustable loads that can follow a preset guidance mechanism completely.

7. A terminal for constructing a power distribution network architecture, comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor when executing the computer program implements a method for constructing a power distribution network architecture as claimed in any one of claims 1 to 6.